CVE-2026-87810: Siyuan-Note Siyuan

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Siyuan before v3.8.2 contains an information disclosure vulnerability in the POST /api/search/fullTextSearchBlock endpoint that filters private blocks from results but returns unfiltered match counts. Unauthenticated publish-mode readers can submit arbitrary search terms to learn whether matching content exists in hidden or unpublished documents and determine the number of matching blocks and pages.

Affected products

• Siyuan-Note Siyuan: before 3.8.2 (fixed in 3.8.2)

Published 2026-09-09. Last modified 2026-09-14.